Subtraction: set t1 to (t2 minus t3)
.text li t0, 13 li t1, 5 # t0=13, t1=5; sub writes 8 to t2. sub t2, t0, t1 1 2 3 4 5
.text li t0, 13 li t1, 5 # t0=13, t1=5; sub writes 8 to t2. sub t2, t0, t1
